Method of manufacturing a light emitting diode element

Abstract

A method of manufacturing a light emitting diode element is provided. A first patterned semi-conductor layer, a patterned light emitting layer, and a second patterned semi-conductor layer are sequentially formed on an epitaxy substrate so as to form a plurality of epitaxy structures, wherein the first patterned semi-conductor layer has a thinner portion in a non-epitaxy area outside the epitaxy structures. A passivation layer covering the epitaxy structures and the thinner portion is formed. The passivation layer covering on the thinner portion is partially removed to form a patterned passivation layer. A patterned reflector is formed directly on each of the epitaxy structures. The epitaxy structures are bonded to a carrier substrate. A lift-off process is performed to separate the epitaxy structures from the epitaxy substrate. An electrode is formed on each of the epitaxy structures far from the patterned reflector.

1. A method of manufacturing a light emitting diode element comprising:
 forming a first patterned semi-conductor layer, a patterned light emitting layer, and a second patterned semi-conductor layer sequentially on an epitaxy substrate so as to form a plurality of epitaxy structures, wherein the first patterned semi-conductor layer has a thinner portion in a non-epitaxy area outside the epitaxy structures; 
 forming a passivation layer covering the epitaxy structures and the thinner portion; 
 removing a part of the passivation layer covering on the thinner portion to form a patterned passivation layer such that the patterned passivation layer has at least a gap corresponding to the thinner portion; 
 forming a patterned reflector directly on each of the epitaxy structures; 
 bonding the epitaxy structures to a carrier substrate; 
 performing a lift-off process to separate the epitaxy structures from the epitaxy substrate; and 
 forming an electrode on each of the epitaxy structures far from the patterned reflector. 
 
     
     
       2. The method of manufacturing a light emitting diode element as claimed in  claim 1 , wherein the method of forming a first patterned semi-conductor layer, a patterned light emitting layer, and a second patterned semi-conductor layer comprises:
 forming a first semiconductor layer, a light emitting layer, and a second semiconductor layer sequentially on the epitaxy substrate; and 
 removing a part of the first semiconductor layer, a part of the light emitting layer, and a part of the second semiconductor layer so that the epitaxy structures are formed and a thickness of the thinner portion is thinner than a thickness of the first semiconductor layer. 
 
     
     
       3. The method of manufacturing a light emitting diode element as claimed in  claim 1 , wherein the method of forming the patterned first semiconductor layer comprises forming the thinner portion having a first thinner portion and a second thinner portion, the second thinner portion is located between the first thinner portion and the epitaxy structures, and the first thinner portion is thinner than the second thinner portion. 
     
     
       4. The method of manufacturing a light emitting diode element as claimed in  claim 3 , wherein the method of removing the part of the passivation layer covering on the thinner portion comprises partially removing a part of the passivation layer directly on the first thinner portion. 
     
     
       5. The method of manufacturing a light emitting diode element as claimed in  claim 1 , wherein the method of removing the part of the passivation layer covering on the thinner portion comprises:
 forming a plurality of nano-cover balls on the passivation layer above the thinner portion; and 
 removing the part of the passivation layer and the underlying thinner portion by using the nano-cover balls as a mask so as to form a plurality of nano-pillars in the non-epitaxy area. 
 
     
     
       6. The method of manufacturing a light emitting diode element as claimed in  claim 5 , wherein the method of forming the nano-cover balls comprises:
 forming a metal layer on the passivation layer in the non-epitaxy area; and 
 performing a high temperature process so as to form the nano-cover balls. 
 
     
     
       7. The method of manufacturing a light emitting diode element as claimed in  claim 6 , wherein a process temperature of the high temperature process is 800° C. to 950° C. 
     
     
       8. The method of manufacturing a light emitting element diode element as claimed in  claim 5 , wherein the method of removing the part of the passivation layer covering on the thinner portion further comprises:
 forming the nano-cover balls and a patterned mask layer covering the epitaxy structures; and 
 removing the part of the passivation layer and the underlying thinner portion by using the nano-cover balls and the patterned mask layer as the mask so as to form the nano-pillars in the non-epitaxy area. 
 
     
     
       9. The method of manufacturing a light emitting diode element as claimed in  claim 5 , wherein a material of the nano-cover balls comprises Ni. 
     
     
       10. The method of manufacturing a light emitting diode element as claimed in  claim 1 , wherein the method of bonding the epitaxy structures to the carrier substrate comprises performing a eutectic connection process. 
     
     
       11. The method of manufacturing a light emitting diode element as claimed in  claim 10 , wherein the method of performing the eutectic connection process comprises:
 forming an adhesive layer on the carrier substrate; and 
 connecting the patterned reflectors to the carrier substrate through the adhesive layer. 
 
     
     
       12. The method of manufacturing a light emitting diode element as claimed in  claim 11 , further comprises forming a barrier layer on the patterned reflectors before performing the eutectic connection process so that the patterned reflectors are connected to the carrier substrate through the barrier layer and the adhesive layer. 
     
     
       13. The method of manufacturing a light emitting diode element as claimed in  claim 11 , wherein a material of the adhesive layer comprises AuSn or Au. 
     
     
       14. The method of manufacturing a light emitting diode element as claimed in  claim 1 , wherein the method of bonding the epitaxy structures to the carrier substrate comprises:
 forming a seed layer on the epitaxy substrate; and 
 performing an electroplating process or an electroless plating process to form the carrier substrate. 
 
     
     
       15. The method of manufacturing a light emitting diode element as claimed in  claim 1 , wherein the method of forming the patterned reflector directly on each of the epitaxy structures comprises removing another part of the passivation layer covering on a top of each of the epitaxy structures and forming the patterned reflector on the top of each of the epitaxy structures. 
     
     
       16. The method of manufacturing a light emitting diode element as claimed in  claim 1 , wherein a thickness of the passivation layer is from 0.1 um to 1 um. 
     
     
       17. The method of manufacturing a light emitting diode element as claimed in  claim 1 , wherein a thickness of the passivation layer is from 0.3 um to 0.9 um. 
     
     
       18. The method of manufacturing a light emitting diode element as claimed in  claim 1 , wherein a thickness of the passivation layer is from 0.3 um to 0.6 um. 
     
     
       19. The method of manufacturing a light emitting diode element as claimed in  claim 1 , wherein the epitaxy substrate is a sapphire substrate. 
     
     
       20. The method of manufacturing a light emitting diode element as claimed in  claim 1 , wherein the lift-off process comprises a laser lift-off process.